Belt Conveyor

Equipment Overview

A belt conveyor is a continuous conveying device that uses a flexible conveyor belt as both the material carrier and traction component, relying on the principle of friction drive to achieve continuous material transport. It is one of the most fundamental and core conveying equipment in modern industrial production and logistics systems, often referred to as the "arteries" of the logistics system.

A telescopic belt conveyor is a special conveying device that adds a telescopic mechanism to a standard belt conveyor. It can freely extend and retract along its length, achieving a flexible connection between fixed loading/unloading points and variable target points (such as inside trucks or containers). Its segmented, nested design, resembling a telescope, allows for significant adjustment of the operating length.

Equipment Structure Composition

(I) Standard Structure of Fixed Belt Conveyor

1. Conveyor Belt: The core load-bearing component; wear-resistant troughed rubber belts are commonly used in fertilizer plants; troughed idlers create a U-shape to prevent powder spillage; heat-resistant belts can be selected for high-temperature conditions, and acid- and alkali-resistant rubber belts are used for acid and alkali fertilizers.

2. Support Idler System

1）Troughed load-bearing idlers: Support the belt when fully loaded with materials;

2）Return flat idlers: Support the empty belt;

3)Self-aligning idlers: Automatically correct belt misalignment.

3. Roller Assembly

1）Drive Roller (Head): Surface coated with rubber to increase friction, driven by a motor and reducer;

2）Idling Roller (Tail): Changes the direction of the belt loop;

4. Drive Unit: Standard motor + reducer / electric roller, frequency conversion speed control optional;

5. Tensioning Device: Tail-end spiral tensioning / counterweight tensioning, adjusts belt tension and prevents slippage;

6. Frame: Channel steel / square tube welded fixed bracket, floor-mounted;

7. Auxiliary Accessories: Feed chute, belt cleaner, side guards, dust cover, backstop, emergency stop switch.

(II) Unique Structure of Telescopic Belt Conveyors (Additions to Ordinary Belt Conveyors)

1. Nested Telescopic Frame: 2–4 sliding rail telescopic sections, chain/rack and pinion driven telescopic movement;

2. Belt Storage Bin: Built-in multiple guide rollers automatically store/release excess belt during telescopic movement, maintaining belt tension throughout;

3. Hydraulic Lifting System: Cylinder-supported height adjustment for different truck bodies;

4. Dedicated Telescopic Drive Motor: Dual motor configuration, one controlling belt conveying and the other controlling machine telescopic movement;

5. Safety Control System: Front-end anti-collision photoelectric sensor, emergency stop, anti-pinch protection, and remote telescopic function; The structures of other belts, idlers, rollers, and cleaners are the same as ordinary belt conveyors.

Applicable Raw Materials

1. Fixed Belt Conveyor Compatible Materials (All Types of Fertilizer)

1) Powdered Raw Materials: Fermented chicken manure powder, humic acid, bentonite, coated talc powder, chemical fertilizer powder;

2) Granular Materials: Granulated organic fertilizer, compound fertilizer, cooled coated finished granules;

3) Lump Materials: Straw, mushroom residue, oilseed cake, small pieces of fermented compost;

4) Finished Bagged Materials: 5kg/20kg/50kg bagged fertilizer; Limitations: Large hard stones and highly sticky mud clumps are prone to clogging; direct conveying is not recommended.

2. Telescopic Belt Conveyor Compatible Materials

Only suitable for bagged finished fertilizer (10–60kg woven bags/coated bags) and boxed fertilizer; cannot convey powdery or bulk granules (expansion joints easily leak powder, no sealed structure).

Working Principle

1. Working Principle of Belt Conveyor

The belt conveyor operates based on the principle of friction drive:

1) Power Output: The drive motor, after being reduced in speed and increased in torque by a reducer, drives the drive drum to rotate;

2) Friction Traction: The tensioning device maintains sufficient positive pressure between the conveyor belt and the drive drum, generating friction; as the drum rotates, the friction drives the closed conveyor belt to run continuously in a preset direction;

3) Material Loading: The material is placed on the conveyor belt and moves synchronously with the belt due to the friction of the belt surface; the load-bearing idler supports the loaded belt, and the return idler supports the unloaded belt;

4) Unloading and Return: After the material reaches the unloading point at the head of the conveyor, it is unloaded by gravity or by the unloading plow; the unloaded belt is turned back by the tail reversing roller and returns to the starting point to enter the next cycle.

Core Formula: Transport Capacity (tons/hour) = 3600 × Belt Speed ​​(m/s) × Material Density (t/m³) × Effective Cross-sectional Area (m²). Belt width, belt speed, and material characteristics are the three key variables determining the conveying capacity.

2. Working Principle of Telescopic Belt Conveyor

Based on the principle of a regular belt conveyor, the telescopic belt conveyor adds a length adaptive mechanism:

1) Telescopic Action: An independent telescopic motor drives the traction translation frame, which slides relative to the outer frame via wire rope or chain traction, allowing for free adjustment of the overall machine length;

2) Belt Length Adaptation: During telescopic movement, the Z-shaped reversing section in the belt storage bin automatically retracts or releases excess belt, maintaining a match between the belt length and the frame length;

3) Bidirectional Operation: The conveyor belt can rotate in both directions, enabling both loading and unloading; combined with height adjustment, it can precisely connect to truck beds or containers of different specifications.

Standard Operation and Maintenance Methods

General Operating Procedures (Applicable to both types of equipment)

1. Start-up Sequence: Start the equipment under no-load conditions → Run under no-load conditions for 3 minutes without abnormal noise before feeding/loading bagged materials; Do not start under heavy load.

2. Shutdown Sequence: First stop feeding, wait until all material on the conveyor belt is cleared, then turn off the main motor.

3. Safety Prohibitions: Do not cross the conveyor belt or reach into the rollers/idlers during operation; power must be disconnected and a sign posted before maintenance; wear insulated gloves when operating electrical circuits, and ensure the equipment is properly grounded before starting.

(I) Graded Maintenance of Fixed Belt Conveyors

1. Daily Inspection: Check for belt misalignment and damage; clean material stuck to the sweeper; check for jammed idlers; check for accumulated fertilizer on the rollers; test the emergency stop and backstop functions;

2. Weekly Lubrication: Add grease to the head and tail roller bearings and self-aligning idler bearings;

3. Quarterly Maintenance: Check the gear oil level in the reducer and replace it with new gear oil every 4 months; clean and lubricate the tensioning device screw;

4. Annual Overhaul: Repair/replace vulcanized belt joints; replace worn idlers and rollers as a whole; correct the overall machine frame level.

(II) Special Maintenance for Telescopic Belt Conveyors

1. Daily: Clean fertilizer dust and debris from the telescopic slide rails to prevent jamming; check the front-end anti-collision photoelectric sensor and emergency stop switch;

2. Weekly: Lubricate the telescopic chain/rack; check the hydraulic oil level in the tank for leaks; clean the belt sweeper;

3. Monthly: Lubricate the bearings of the telescopic drive motor; check the seals of the lifting hydraulic cylinder;

4. Quarterly: Inspect the wear of the entire slide rail; tighten all loose fasteners; clean the frequency converter control system.

List of Vulnerable Parts

1. Fixed Belt Conveyors: Rubber conveyor belt, idlers, sweeper blades, roller bearings, belt joints, anti-backflow brake pads;

2. Telescopic Belt Conveyors: Conveyor belt, telescopic slide rail slider, telescopic chain, hydraulic seal, anti-collision photoelectric sensor head.

Application Processes of Two Types of Equipment in Fertilizer Production Lines

1. Fixed Belt Conveyor System (Core Production Line Link): Raw Material Yard → Belt Conveyor → Crusher → Belt Conveyor → Batching and Mixing Machine → Belt Conveyor → Granulator → Belt Conveyor → Rotary Drum Dryer → Rotary Drum Cooler → Belt Conveyor → Coating Machine → Screening Machine → Belt Conveyor → Finished Product Silo → Packaging Machine. Function: Transports powdery and granular semi-finished products throughout the entire process, connecting all main equipment and ensuring continuous production on the assembly line.

2. Telescopic Belt Conveyor System (Finished Product End Only): Packaging Machine Discharge Port → Short-Distance Fixed Belt Conveyor → Telescopic Belt Conveyor → Truck/Container Carriage. Function: Used only for loading and unloading bagged fertilizer after packaging; does not participate in upstream drying, granulation, or other processes; it is an auxiliary equipment for warehousing and logistics.

In summary, belt conveyors form the "basic framework" of industrial material handling, boasting advantages such as simple structure, large capacity, long distance, and low energy consumption. They are widely used in heavy-duty and long-distance scenarios in mining, ports, manufacturing, and agriculture. Telescopic belt conveyors, on the other hand, act as the "flexible arm" at the end of the logistics chain. Building upon ordinary belt conveyors, they add adaptive length and height adjustment capabilities, specifically addressing the high-frequency, variable, and labor-intensive process of vehicle loading and unloading.

The two are not substitutes but rather complementary and synergistic: belt conveyors construct the main logistics channels of the production line, while telescopic conveyors complete the final link in loading and unloading. In modern smart factories and intelligent logistics systems, both are deeply integrated with automated sorting, robotic palletizing, and WMS/WCS systems, jointly forming an efficient, continuous, and flexible material handling ecosystem.