Equipment Introduction
The rotary drum screener, also known as a drum screen or rotary sieve, is the most widely used grading and screening equipment in the production of organic fertilizer, compound fertilizer, and compound fertilizer. This machine is mainly used for separating finished products from returned materials, and can also achieve product grading, resulting in uniformly classified finished products. It adopts a modular screen design, facilitating maintenance and replacement. Its overall structure is simple, easy to operate, and runs smoothly, making it an ideal piece of equipment in compound fertilizer production.
The rotary drum screener is a new generation of self-cleaning screening equipment following the electric vibrating screen. It is widely applicable to the screening of various solid materials with a particle size of less than 300mm, and features high screening efficiency, low noise, low dust generation, long service life, low maintenance, and convenient inspection. It acts like a precise "ruler," accurately measuring the size of each fertilizer particle in the production line.
Equipment Structure Composition
The entire machine is divided into three main parts: the frame assembly, the drum screen body, and the transmission system, as well as the infeed/outfeed and auxiliary accessories.
1. Frame Assembly: A lightweight, integrally welded support frame made of channel steel and steel plates, eliminating the need for a heavy base. It features separate hoppers for finished products, fine powder, and coarse materials, providing multi-channel material collection.
2. Drum Screen Body (Core): A cage-type drum spindle is installed at a 5°~15° inclination. The drum body is segmented and equipped with perforated screens (carbon steel/304 stainless steel optional). The drum contains internal lifting ribs to enhance material tumbling and dispersing. Bearing seats at both ends support the drum rotation.
3. Transmission System: A standard motor + V-belt + ZQ series reducer + sprocket and chain drive; providing stable low-speed torque output and easy disassembly and maintenance of transmission components.
4. Supporting Auxiliary Components: A fully enclosed dust cover, infeed flange, three-channel discharge chutes, anti-clogging beater rollers, inspection and observation port, and grounding protection.
Working Principle of the Equipment
The working principle of the drum screen is based on the combined effect of gravity and centrifugal force:
1. Material Input and Rotation
The material enters the equipment through the feed inlet at the high end of the drum. The motor drives the drum to rotate via a reducer, and the drum rotates at a constant speed of 10-15 r/min. The drum is installed at an inclination angle of 2-5° to the ground.
2. Material Tumbling and Grading
During the drum rotation, the material is continuously tumbled and rolled. Fine materials pass through the screen and are discharged below the screen, while coarse materials move along the inner wall of the drum to the lower end and are discharged from the bottom tail of the drum.
3. Multi-stage Separation
According to different grading requirements, the drum can be designed as a multi-layer sleeve structure, with each layer having a filter screen of different aperture size. As the material passes through the screens of different aperture sizes, it is separated into multiple particle size grades.
4. Separation of Finished Products and Returned Materials In fertilizer production, finished product granules that meet the specifications fall through the screen into the finished product collection area, while oversized granules or clumps that do not meet the specifications are discharged from the end of the roller and returned to the production line for reprocessing as returned materials.
Applicable Raw Materials
| Material Category | Applicable Materials | Material Matching Requirements & Features |
|---|---|---|
| Fertilizer Raw Materials | Organic fertilizer granules (pig manure, chicken manure, cattle manure, sheep manure and other livestock manure), compound fertilizer granules, compound‑mixed fertilizer granules, bio‑organic fertilizer granules, powdery fertilizer | Suitable for various powdery and granular fertilizers. Uniform screening precision, meets fertilizer grading, impurity removal and finished‑product screening process requirements |
| Organic Wastes | Kitchen waste, rotten fruits, rotten vegetable leaves, straw, plant waste, plant ash, biogas residue | Suitable for various loose organic wastes. Realizes solid‑waste sorting, impurity removal and grading for resource recycling treatment processes |
| Industrial Raw Materials | Coal, coke, lime, various ores, sand, gravel | Matches bulk solid industrial raw materials. Performs coarse‑fine grading and impurity purification for sand, coal and ores |
| General Material Requirements | Powdery, granular and small‑block solid materials | Applicable material size ≤300mm. Core advantages: adapts to damp and easily‑caking materials. Rotary drum self‑cleans, screen holes resist blocking, stable screening performance |
Application of Equipment in the Production Line
1. Core Position in the Fertilizer Production Line
The drum screen plays the role of "quality gatekeeper" in the fertilizer production line. It is usually located after drying and cooling and before packaging, serving as the final checkpoint before the finished product leaves the factory.
Complete Processing Flow:
Raw Material Pretreatment → Fermentation and Composting → Crushing → Ingredient Mixing → Granulation → Drying → Cooling → Drum Screening → Coating → Packaging
2. Specific Functions in the Production Line
(1) Separation of Finished Products and Returned Materials
Finished product granules that meet specifications pass through the screen to the next process, while oversized granules or clumps that do not meet specifications are returned to the production line for reprocessing.
(2) Finished Product Grading
The finished products are divided into multiple grades according to particle size through screens of different apertures, ensuring uniform classification.
(3) Pre-screening of Fermentation Material
Stones, large impurities, etc., are removed from the material before or after fermentation.
(4) Grading after Granulation
The granulated particles are graded according to particle size, separating qualified finished products from unqualified returned materials.
3. Screen mesh size selection
| Application Scenario | Recommended Screen Aperture | Screen Material |
|---|---|---|
| Pre‑screening of Fermented Material | 10‑20mm | Manganese Steel Woven Mesh / Perforated Plate |
| Finished‑product Grading after Granulation | 2‑4.5mm | Stainless Steel / High‑Carbon Steel / Manganese Steel |
4. Special design: For screening semi-wet materials, the mesh is prone to clogging, generally requiring the installation of an anti-clogging impact device. Some equipment also features a plate-type automatic screen cleaning mechanism for automatic cleaning.
Common Faults, Causes, and Standardized Solutions
| Fault Phenomenon | Root Cause | Professional Solutions |
|---|---|---|
| Poor screening accuracy, oversize material mixed with plenty of qualified granules | Damaged screen mesh; excessive feeding flow; blocked screen holes; too small drum inclination angle | 1.Replace damaged screen; 2.Reduce upstream feeding speed; 3.Activate beating device for mesh cleaning; 4.Adjust drum inclination angle |
| Frequent screen clogging, sharp drop of screening efficiency | High fertilizer moisture, no beating self‑cleaning device | Add external beating hammers; stop machine regularly to flush screen mesh |
| Abnormal drum noise, metal scraping sound | Bearing wear due to insufficient lubrication; loose chain hitting frame; hard lumps fallen into drum | Fill grease for bearings; tension drive chain; shut down and remove hard foreign objects inside drum |
| Motor overload, trip‑off shutdown | Start‑up with residual materials inside drum; instantaneous overloading of feeding | Strictly follow the rule: stop feeding first then empty materials before shutdown; maintain uniform feeding speed |
| Drum reverse rotation, disordered discharging | Wrong phase connection of motor power cable | Swap any two three‑phase power wires to correct rotation direction |
| Slipping of drive chain / V‑belt | Worn transmission parts, insufficient tension | Replace worn belt / chain; adjust tension pulley for proper tightness |
Summary of Equipment's Comprehensive Technical Features:
1. Low vibration and easy installation: No heavy concrete foundation required; suitable for retrofitting both new and old workshops.
2. Self-cleaning and anti-clogging design suitable for wet fertilizer: Double cleaning with tumbling and beating ensures stable screening of high-moisture organic fertilizer.
3. Flexible grading: Segmented combined screens allow for simultaneous coarse, medium, and fine three-stage sorting.
4. Excellent finished product protection: Low particle breakage rate during low-speed operation results in better fertilizer product appearance.
5. Simple operation and maintenance: Standardized wear parts and screen clamps allow for quick replacement by a single person.
6. Environmentally friendly and enclosed: Equipped with a fully enclosed dust cover, eliminating dust pollution in the screening section and meeting environmental acceptance standards.
| Model | Barrel | Rotation Speed | Inclination | Power | Capacity | Dimensions | Weight | |
| Diameter | Length | L× W × H | ||||||
| mm | mm | r/min | 0 | kW | t/h | mm | tons | |
| GS1.0×3.0 | 1000 | 3000 | 22 | 2-2.5 | 2.2 | 1-3 | 3500×1400×2200 | 1.5 |
| GS1.2×4.5 | 1200 | 4500 | 17 | 2-2.5 | 3.0 | 3-5 | 5700×1600×2400 | 2.5 |
| GS1.5×5.0 | 1500 | 5000 | 14 | 2-2.5 | 5.5 | 5-10 | 6860×1900×2810 | 3.8 |
| GS1.0×3.0 | 1000 | 3000 | 22 | 2-2.5 | 2.2 | 10-20 | 3500×1400×2200 | 1.5 |
| GS1.6×6.0 | 1600 | 6000 | 12 | 2-2.5 | 7.5 | 10-20 | 7300×2000×3000 | 4.7 |
| GS1.2×4.0 | 1200 | 4000 | 16 | 2-2.5 | 3.0 | 20-25 | 5200×600×2360 | 2.3 |
| GS1.8×6.5 | 1800 | 6500 | 11.5 | 2-2.5 | 7.5 | 20-25 | 9000×2200×3200 | 6.0 |
